Clojureのtest.checkで乱数列をサンプルするにはどうすればよいですか？

Question

私はSubset Sum Problemのランダムな解決可能なインスタンスを生成しようとしています。 Wikipediaは、目標値は常にゼロであるべきだと述べていますが、目標値を指定することもできます。これは私がここでやっていることです。

したがって、(gen/vector gen/int)を使用してランダムベクトルを作成し、次にランダムなサブベクトルをサンプリングし、そのベクトルを合計してターゲット値を作成することです。 gen/elementsを使用した明らかな戦略の問題は、同じ要素を繰り返しサンプリングする可能性があることです。
私の次善の考えは、インデックスのランダムなセットを作成し、それらのインデックスのすべての要素を抽出することです。より簡単なアプローチはありますか？

Answer 1

This generator in test.chuck各要素のインクルージョンフラグを生成することによって、あなたが求めていることを実行します。

Answer 2

このコードは、あなたがしようとしていると思われるもののモックアップです。それは、整数のベクトルを生成します。整数のベクトルは、それぞれがサブセットに属しているかどうかを示すフラグ（none、some、またはall）を持ちます。ダミー関数（standin for subset-sum）は、テストに合格するかどうかを決定します。 project.cljに[tupelo "0.9.56"]が必要です。

(ns tst.demo.core 
    (:require 
    [clojure.test.check :as tc] 
    [clojure.test.check.generators :as tcgen] 
    [clojure.test.check.properties :as tcprop] 
    [tupelo.core :as t] 
    [tupelo.test :as tt] 
    [schema.core :as s])) 

(def IntBoolTuple [ (s/one s/Int "x1") (s/one s/Bool "x2") ]) 

(s/defn is-sum-tuple? :- s/Bool 
    [tuple :- IntBoolTuple] 
    (let [[int-val bool-val] tuple] 
    bool-val)) 

(s/defn tst-fn :- s/Bool 
    "Dummy test function" 
    [tuples :- [IntBoolTuple]] 
    (let [all-ints  (mapv first tuples) 
     flags   (mapv second tuples) 
     tuples-to-add (vec (filter is-sum-tuple? tuples)) 
     ints-to-add (mapv first tuples-to-add) 
     int-sum  (apply + ints-to-add)] 
    (< -20 int-sum))) ; dummy test: pass if not too negative 

(tt/dospec 999 
    (tcprop/for-all [tuples (tcgen/such-that 
          (fn st-fn [tuples] (pos? (count tuples))) ; ensure at least 1 tuple is present 
          (tcgen/vector ; 0 or more tuples, ex: [ [5 false] [2 true] ...] 
           (tcgen/tuple tcgen/int tcgen/boolean) ; a tuple like [5 false] 
          ))] 
    (t/spyx tuples) ; display 
    (tst-fn tuples))) 

上記のコードは次のように出力を生成します。

--------------------------------------- 
    Clojure 1.9.0-beta1 Java 9.0.1 
--------------------------------------- 

Testing tst.demo.core 
tuples => [[-1 false]] 
tuples => [[1 true]] 
tuples => [[-2 true] [-1 false]] 
tuples => [[3 true] [-1 true]] 
tuples => [[1 true]] 
tuples => [[-1 true] [5 true] [-4 true] [5 false]] 
tuples => [[5 true] [2 false] [3 false] [1 true] [0 true]] 
tuples => [[2 false] [-4 false]] 
tuples => [[2 false]] 
tuples => [[2 false] [8 true] [9 true] [9 true] [3 true] [-7 true] [-9 true] [8 false] [-9 true]] 
tuples => [[-9 true] [-1 true]] 
tuples => [[4 false] [-6 true] [0 false] [10 true]] 
tuples => [[-2 false] [7 true] [-12 false] [4 false] [4 false] [11 true] [6 false] [-5 false]] 
tuples => [[-5 false] [6 true] [9 true] [-7 true] [1 false] [3 false] [-9 true] [-9 true] [-8 true] [-8 false] [-12 false]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[8 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-14 true] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-14 true] [-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-14 true] [-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-1 false] [-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-1 false] [-14 true] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-1 false] [-14 true] [-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[-1 false] [-14 true] [-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[-1 false] [-14 true] [-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[-10 false] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 true] [-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-14 true] [-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[-14 true] [-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[-14 true] [-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[-14 true] [-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[-8 true] [1 false] [5 false] [-13 true]] 
tuples => [[-10 false] [1 false] [5 false] [-13 true]] 
tuples => [[-10 false] [-8 true] [5 false] [-13 true]] 
tuples => [[-10 false] [-8 true] [1 false] [-13 true]] 
tuples => [[-10 false] [-8 true] [1 false] [5 false]] 
tuples => [[1 false] [5 false] [-13 true]] 
tuples => [[-8 true] [5 false] [-13 true]] 
tuples => [[-8 true] [1 false] [-13 true]] 
tuples => [[-8 true] [1 false] [5 false]] 
tuples => [[5 false] [-13 true]] 
tuples => [[-8 true] [-13 true]] 
tuples => [[-8 true] [5 false]] 
tuples => [[-13 true]] 
tuples => [[-8 true]] 
tuples => [[0 true] [-13 true]] 
tuples => [[-4 true] [-13 true]] 
tuples => [[-6 true] [-13 true]] 
tuples => [[-7 true] [-13 true]] 
tuples => [[-8 false] [-13 true]] 
tuples => [[-13 true]] 
tuples => [[-7 true]] 
tuples => [[0 true] [-13 true]] 
tuples => [[-4 true] [-13 true]] 
tuples => [[-6 true] [-13 true]] 
tuples => [[-7 false] [-13 true]] 
tuples => [[-7 true] [0 true]] 
tuples => [[-7 true] [-7 true]] 
tuples => [[-7 true] [-10 true]] 
tuples => [[-7 true] [-12 true]] 
tuples => [[-7 true] [-13 false]] 
{:result false, :seed 1511919758351, :failing-size 14, :num-tests 15, :fail [[[-7 false] [-14 false] [8 false] [-1 false] [-14 true] [-10 false] [-8 true] [1 false] [5 false] [-13 true]]], :shrunk {:total-nodes-visited 27, :depth 9, :result false, :smallest [[[-7 true] [-13 true]]]}, :test-var "dospec-line-46"} 

FAIL in (dospec-line-46) (clojure_test.cljc:21) 
expected: result 
    actual: false